Warehouses typically include one or more loading docks for transferring goods to and from over road trailers. Conventional loading docks usually consist of an opening in a side of the warehouse. The opening is typically covered by a roll up door, and is usually positioned a few feet above the ground to be approximately level with shipping trailers. To load or unload goods, the doors on an aft end of the trailer are opened and the trailer is backed up to the loading dock opening. Workers can then pass into the trailer through the opening to load or unload goods.
There are various types of loading dock enclosures that are used for sheltering and/or sealing the open end of the trailer during the loading and unloading process. Such shelters are described in, for example, U.S. Pat. Nos. 4,213,279; 4,601,142; 4,711,059; 4,718,207; 4,799,342; 4,885,881; 5,282,384; 5,953,868; and 6,311,435; U.S. Patent Publication Nos. 2003/0177720; and 2004/0134139; and International Patent Publication No. WO 2006/052661. Each of the aforementioned patents and patent applications are incorporated into the present disclosure in its entirety by reference.
Many conventional loading dock seals comprise resilient, compressible pads that are attached to the building along the lateral and top edges of the doorway. The pads usually include a foam core, which is covered with a coated vinyl fabric or other similar covering for protection and appearance. The pad compliantly conforms to the rear contour of the aft end of the trailer as the trailer presses up against the pad, which helps seal the gap between the face of the building and the trailer. Although dock seals provide excellent sealing, they are often subject to significant compressive forces that can shorten the life of the seal. For example, as the trailer engages the dock seal, the fabric cover of the dock seal is subjected to compressive forces between the trailer and the pad, and the fabric cover can be punctured or otherwise damaged. Moreover, as the trailer moves up and down during loading/unloading, abrasive forces can also wear through the fabric cover. When the fabric becomes punctured, the foam core can become exposed and damaged. As a result, the dock seals may require relatively frequent repair or replacement.